1. Field of the Invention
The present invention relates generally to a spray flow control system, and in particular to asphalt sealant material with vehicle mounted spraying equipment and dedicated prime mover, and in more particularly to a speed sensing digital positioning system such as a global positioning system (GPS) or horn radar, and motor RPM sensing for a pump responsive flow control system.
2. Description of the Related Art
A vehicle mounted spray control system, having means of maintaining a correct spray application rate through vehicle speed and product pressure sensing is a known and commonly utilized system. Such a system will generally include a material tank, a pump for conveying fluid under pressure from the material tank to a spray bar, a speed sensor to calculate speed the of the vehicle, a pressure sensor near the spray head, and a programmed processor to calculate and adjust the pump output to achieve the target application spray rate, using the inputs of the speed and pressure sensors.
However, a disadvantage with many vehicle-mounted spray systems relates to the vehicle mounting capabilities of the spray system. The past spray systems are not exclusive to a dedicated prime mover for the spray system. Generally the material pump is connected to the vehicle drive shaft with the power taken off the vehicle engine. Having a dedicated prime mover for the spray system, not having to physically integrate the spray system directly into the provided vehicle, provides simple mounting capabilities. Means of speed sensing is also generally integrated into the vehicle and is commonly accomplished at the wheel of the vehicle.
Digital positioning, such as GPS and horn radar, is proven to be a reliable technology. The present invention integrates a digital positioning receiver as means for speed sensing, which provides wireless speed sensing capabilities. A digital positioning receiver eliminates the steps of sizing specific wheel diameters and physically integrating the spray system into the vehicle. The combination of a digital positioning receiver for speed sensing and a dedicated prime mover provides a versatile spray unit with unproblematic mounting capabilities.
In addition to the digital positioning wireless speed sensing, the present invention utilizes a wireless remote control of spray system. Generally on/off control of the spray system takes place at the operator control panel where the CAN micro processor and CAN digital display are located. A wireless remote control allows the operator to detach themselves from the spray unit, giving them the opportunity to physically see the flow of the product, check the consistency of the application, and to ultimately have an additional source of control of the spray system.
In relation to regulating product flow, it is also generally the case to have a pressure sensor near the spray head to be used as an input at the processor to calculate and adjust the output flow of the pump. Because of the inconsistency in asphalt sealant material, the present invention introduces new means of controlling the output flow of the pump. Rather than using pressure sensing as an input to calculate output flow of the pump, a RPM sensor can sense the rotation of the hydraulic motor which drives the pump. Given that 1 RPM at the motor equals X amount of product flow, the information from the RPM sensor can be used as an input at the processor to calculate and adjust the flow of product to the spray bar proportionate to the speed of the vehicle adjusted to the operator established spray percentage.
Past spray systems are primarily but not exclusively intended for asphalt sealant spray applications. The asphalt industry has yet to be introduced to high volume, cost efficient means of asphalt sealant application. A large product tank and simple vehicle mounting capabilities eliminates the need for a custom made, large volume asphalt sealant spray vehicle. The public can simply mount the digital positioning spray unit on a variety of truck and trailer beds.